Generation of a radially polarized laser beam by use of a conical Brewster prism

To generate a radially polarized laser beam we designed and fabricated a new Brewster optical element that consists of convex and concave conical prisms. The lateral surface of the convex conical prism was coated with a dielectric multilayer (SiO₂ and Ta₂O₅) to enhance polarization selectivity. By combining two prisms we obtained a conical Brewster prism without beam divergence owing to refraction. A radially polarized TEM₀₁* (R-TEM₀₁*) mode laser beam was demonstrated when this prism was used inside a Nd:YAG laser cavity.